Search Results (75)

Silk fibroin (SF) has evolved from a traditional biopolymer to a leading regenerative medicine material. Its combination of mechanical strength, biocompatibility, tunable degradation, and molecular adaptability makes SF a unique matrix that is both bioactive and intelligent. Advances in hydrogel engineering have transformed SF from a passive scaffold into a smart, living hydrogel. These systems can instruct cell fate, sense microenvironmental signals, and deliver therapeutic signals as needed. By incorporating stem cells, progenitors, or engineered immune and microbial populations, SF hydrogels now serve as synthetic niches for organoid maturation and as adaptive implants for tissue regeneration. These platforms replicate extracellular matrix complexity and evolve with tissue, showing self-healing, shape-memory, and stimuli-responsive properties. Such features are redefining biomaterial–cell interactions. SF hydrogels are used for wound healing, musculoskeletal repair, neural and cardiac patches, and developing scalable organoid models for disease and drug research. Challenges remain in maintaining long-term cell viability, achieving clinical scalability, and meeting regulatory standards. This review explores how advances in SF engineering, synthetic biology, and organoid science are enabling SF-based smart living hydrogels in bridging the gap between research and clinical use. Full article

Mitochondrial dysfunction is a key contributor to cardiac injury and heart failure, and extracellular vesicles (EVs) have emerged as promising therapeutic agents due to their ability to deliver mitochondrial-targeted cargo. This review systematically maps the evidence on how EVs modulate mitochondrial dynamics—including fusion, fission, mitophagy, and biogenesis—in regenerative cardiology. We comprehensively searched PubMed, Scopus, and Web of Science up to September 2025 for original studies. A total of 48 studies were included, with most utilizing EVs from mesenchymal stem cells, induced pluripotent stem cells, or cardiac progenitors. The review found that EV cargo influences key pathways such as DRP1 and MFN2, restores mitochondrial membrane potential, reduces ROS accumulation, and improves cardiomyocyte survival. While engineered EVs showed enhanced specificity, a lack of standardized preparation and quantitative assessment methods remains a significant challenge. We conclude that EV-mediated mitochondrial modulation is a promising strategy for cardiac repair, but the field needs harmonized protocols, deeper mechanistic understanding, and improved translational readiness to advance beyond preclinical research. The future of this research lies in integrating systems biology and precision targeting. Full article

Circular RNAs (circRNAs) are looped RNA molecules with regulatory roles in myocardial infarction and post-infarction cascades. We aimed to (i) confirm the circularity of novel circRNAs (CDR1as, circ-RCAN2, circ-C12orf29) implicated in myocardial infarction, (ii) examine cell-specific regulation patterns under hypoxia, and (iii) assess their effects on cell viability and downstream miRNA targets. Experiments were conducted on porcine cardiac progenitor cells (pCPCs), bone marrow mesenchymal stem cells (pMSCs) and cardiac fibroblasts (pCFs). Circularity was assessed by RNase R treatment, subsequent qPCR, gel electrophoresis and Sanger sequencing. Hypoxia experiments with/without serum deprivation mimicked ischemia. Effects on viability with/without hypoxia (MTT assay) and downstream miRNA targets were assessed via short interfering RNA (siRNA)-mediated knockdown of circ-RCAN2 and circ-C12orf29. Following RNase R treatment, qPCR product electrophoresis demonstrated amplification of singular products for all circRNAs, with backsplice junction amplification confirmed via Sanger sequencing. Serum deprivation and hypoxia resulted in cell-specific circRNA expression patterns, with an upregulation of all candidates in pCPCs across all intervals of hypoxia, an upregulation of circ-RCAN2 and circ-C12orf29 in pMSCs with prolonged hypoxia, and no detectable dysregulation in pCFs. siRNA knockdown of circ-RCAN2 reduced pCF- and increased pMSC-viability. circ-C12orf29 knockdown increased pCPC- and reduced pMSC-viability. circ-C12orf29 knockdown also upregulated ssc-miR-21-5p and ssc-miR-181c in pCPCs, with no detectable targets for circ-RCAN2. In conclusion, CDR1as, circ-RCAN2 and circ-C12orf29 are circular and dysregulated in a time- and cell-type-specific manner following hypoxia. circ-RCAN2 and circ-C12orf29 exhibit cell-type specific effects on viability, with circ-C12orf29 also targeting downstream miRNAs. Full article

Pathological vascular remodeling—central to restenosis, atherosclerosis, and vasculo-proliferative diseases—depends on the phenotypic switching of vascular smooth muscle cells (VSMCs) from a quiescent, contractile state to a synthetic, proliferative program. Although the receptor tyrosine kinase c-Kit is implicated in proliferation, migration, and tissue repair, its role in VSMC plasticity has yet to be fully understood. Using c-Kit haploinsufficient mice subjected to right carotid artery ligation (CAL) and primary aortic VSMC cultures, we show that c-Kit is required for the contractile-to-synthetic transition. In vitro, c-Kit haploinsufficiency halved c-Kit expression, reduced 5-bromo-2′-deoxyuridine (BrdU) incorporation, and blunted platelet-derived growth factor BB (PDGF-BB)-induced repression of contractile genes. c-Kit–deficient VSMCs exhibited a senescence program with increased p16^INK4a/p21 expression and upregulated senescence-associated secretory phenotype (SASP) mediators. RNA-Seq of carotid arteries 7 days post-ligation revealed that wild-type arteries activated cell-cycle pathways and suppressed contractile signatures, whereas c-Kit-deficient carotid arteries failed to fully engage proliferative programs and instead maintained contractile gene expression. At 28 days post CAL in vivo, c-Kit haploinsufficiency produced markedly reduced neointima, fewer Ki67+ VSMCs, more p16^INK4a+ cells, and impaired re-endothelialization. Because progenitor-to-VSMC differentiation contributes to remodeling, we tested adult cardiac stem/progenitor cells (CSCs) as a model system of adult progenitor differentiation. Wild-type CSCs efficiently generated induced VSMCs (iVSMCs) with appropriate smooth-muscle gene upregulation; c-Kit–deficient rarely did so. Restoring c-Kit with a BAC transgene rescued both the smooth-muscle differentiation and proliferative competence of c-Kit-deficient iVSMCs. Collectively, our data identified c-Kit as a gatekeeper of reparative VSMC plasticity. Adequate c-Kit enables progenitor-to-VSMC commitment and the expansion of newly formed VSMCs while permitting injury-induced proliferation and matrix synthesis; reduced c-Kit locks cells in a hypercontractile, senescence-prone state and limits neointima formation. Modulating the c-Kit axis may therefore offer a strategy to fine-tune vascular repair while mitigating pathological remodeling. Full article

Adipose tissue enlargement in obesity leads to hypoxia, which may promote premature aging. This study aimed to understand the hypoxic response in 3D cultures of SGBS cells, a model for brown-like adipose tissue expressing uncoupling protein 1 (UCP1). Single-nucleus RNA sequencing of SGBS organoids revealed a heterogeneous composition and sub-population-specific responses to hypoxia. The analysis identified a cluster of transcriptional repression, indicating dying cells, and implied a role of ferroptosis in this model. Further experiments with SGBS cells and white adipose tissue-derived stem/progenitor cells showed that Acyl-CoA synthetase long-chain family member 4 (ACSL4), a key enzyme in ferroptosis, is expressed only in the presence of browning factors. Hypoxia downregulated ACSL4 protein in SGBS organoids but induced an inflammaging phenotype. Analysis of brown-like epicardial adipose tissue from cardiac surgery patients revealed a significant positive correlation of ACSL4 mRNA with UCP1 and hypoxia-inducible pro-inflammatory markers, while ACSL4 protein appeared to be inversely correlated. In conclusion, this study demonstrates that adipocytes’ capability to undergo ACSL4-mediated ferroptosis is linked to brown-like adipogenesis, suggesting an opportunity to modulate ferroptotic signaling in adipose tissue. The dual role of hypoxia by inhibiting ACSL4 but promoting inflammaging indicates a relationship between ferroptosis and aging that warrants further investigation. Full article

Cell therapy is promising for heart failure treatment, with growing interest in cardiovascular progenitor cells (CPCs) from pluripotent stem cells. A major challenge is managing the immune response, due to their allogeneic source. Regulatory T cells (Treg) offer an alternative to pharmacological immunosuppression by inducing immune tolerance. This study assesses whether Treg therapy can mitigate the xeno-immune response, improving cardiac outcomes in a mouse model of human CPC intramyocardial transplantation. CPCs stimulated immune responses in allogeneic and xenogeneic settings, causing proliferation in T cell subsets. Tregs showed immunosuppressive effects on T lymphocyte populations when co-cultured with CPCs. Post infarction, CPCs were transplanted intramyocardially into an immune-competent mouse model 3 weeks after myocardial infarction. Human or murine Tregs were intravenously administered on transplantation day and three days later. Control groups received CPCs without Tregs or saline (PBS). CPCs with Tregs improved LV systolic function in three weeks, linked to reduced myocardial fibrosis and enhanced angiogenesis. This was accompanied by decreased splenocyte NK cell populations and pro-inflammatory cytokine levels in cardiac tissue. Treg therapy with CPC transplantation enhances cardiac functional and structural outcomes in mice. Though it does not directly avert graft rejection, it primarily affects NKG2D+ cytotoxic cells, indicating systemic immune modulation and remote heart repair benefits. Full article

The therapeutic potential of presumed cardiac progenitor cells (CPCs) in heart regeneration has garnered significant interest, yet clinical trials have revealed limited efficacy due to challenges in cell survival, retention, and expansion. Priming CPCs to survive the hostile hypoxic environment may be key to enhancing their regenerative capacity. We demonstrate that microRNA-210 (miR-210), known for its role in hypoxic adaptation, significantly improves CPC survival by inhibiting apoptosis through the downregulation of Casp8ap2, a ~40% reduction in caspase activity, and a ~90% decrease in DNA fragmentation. Contrary to the expected induction of Bnip3-dependent mitophagy by hypoxia, miR-210 did not upregulate Bnip3, indicating a distinct anti-apoptotic mechanism. Instead, miR-210 reduced markers of mitophagy and increased mitochondrial biogenesis and oxidative metabolism, suggesting a role in metabolic reprogramming. Furthermore, miR-210 enhanced the secretion of paracrine growth factors from CPCs, with a ~1.6-fold increase in the release of stem cell factor and of insulin growth factor 1, which promoted in vitro endothelial cell proliferation and cardiomyocyte survival. These findings elucidate the multifaceted role of miR-210 in CPC biology and its potential to enhance cell-based therapies for myocardial repair by promoting cell survival, metabolic adaptation, and paracrine signalling. Full article

Both cardiac and skeletal muscles originate from the mesoderm, although the two tissues develop from distinct primordia within the early embryo. The shared, albeit distinctive muscle phenotype of these two cell types have led many researchers to investigate whether stem cells from adult skeletal muscle have the capacity to generate cells with a contractile, cardiac phenotype. To date, most of those studies have relied on multistep protocols requiring tissue engineering, co-cultures or transplantation experimentation. In this report, we describe a simple, cell culture method for obtaining contractile, cardiogenic aggregates from skeletal muscle-derived stem cells (MDSCs). Combining in vitro conditions used for promoting the differentiation of cardiac progenitor cells and the long-term maintenance of heart tissue fragments, we have been able to convert MDSCs to myocardial cells that aggregate into beating myospheres. These selective and optimized culture conditions continued to support a contractile cardiogenic phenotype for over four months in vitro. This culture protocol provides a model for future insights into the pathways responsible for the divergence of skeletal and cardiac phenotypes, as well as a source of easily obtained myocardial tissue for subsequent scientific investigations into cardiac function and biology. Full article

Emery–Dreifuss muscular dystrophy type 1 (EDMD1) is a rare genetic disease caused by mutations in the EMD gene, which encodes the nuclear envelope protein emerin. Despite understanding the genetic basis of the disease, the molecular mechanism underlying muscle and cardiac pathogenesis remains elusive. Progress is restricted by the limited availability of patient-derived samples; therefore, there is an urgent need for human-specific cellular models. In this study, we present the generation and characterization of induced pluripotent stem cell (iPSC) lines derived from EDMD1 patients carrying EMD mutations that lead to truncated or absent emerin, together with iPSCs from healthy donor. The patient-specific iPSCs exhibit stable karyotypes, maintain appropriate morphology, express pluripotency markers, and demonstrate the ability to differentiate into three germ layers. To model EDMD1, these iPSCs were differentiated into myogenic progenitors, myoblasts, and multinucleated myotubes, which represent all stages of myogenesis. Each developmental stage was validated by the presence of stage-specific markers, ensuring the accuracy of the model. We present the first iPSC-based in vitro platform that captures the complexity of EDMD1 pathogenesis during myogenesis. This model can significantly contribute to understanding disease mechanisms and develop the targeted therapeutic strategies for EDMD1. Full article

Sall4 as a pivotal transcription factor has been extensively studied across diverse biological processes, including stem cell biology, embryonic development, hematopoiesis, tissue stem/progenitor maintenance, and the progression of various cancers. Recent research highlights Sall4’s emerging roles in modulating cardiac progenitors and cellular reprogramming, linking its functions to early heart development and regenerative medicine. These findings provide new insights into the critical functions of Sall4 in cardiobiology. This review explores Sall4’s complex molecular mechanisms and their implications for advancing cardiac regenerative medicine. Full article

Heart disease, including myocardial infarction (MI), remains a leading cause of morbidity and mortality worldwide, necessitating the development of more effective regenerative therapies. Direct reprogramming of cardiomyocyte-like cells from resident fibroblasts offers a promising avenue for myocardial regeneration, but its efficiency and consistency in generating functional cardiomyocytes remain limited. Alternatively, reprogramming induced cardiac progenitor cells (iCPCs) could generate essential cardiac lineages, but existing methods often involve complex procedures. These limitations underscore the need for advanced mechanistic insights and refined reprogramming strategies to improve reparative outcomes in the heart. Partial cellular fate transitions, while still a relatively less well-defined area and primarily explored in longevity and neurobiology, hold remarkable promise for cardiac repair. It enables the reprogramming or rejuvenation of resident cardiac cells into a stem or progenitor-like state with enhanced cardiogenic potential, generating the reparative lineages necessary for comprehensive myocardial recovery while reducing safety risks. As an emerging strategy, partial cellular fate transitions play a pivotal role in reversing myocardial infarction damage and offer substantial potential for therapeutic innovation. This review will summarize current advances in these areas, including recent findings involving two transcription factors that critically regulate stemness and cardiogenesis. It will also explore considerations for further refining these approaches to enhance their therapeutic potential and safety. Full article

Myocardial infarction (MI) is a critical global health issue and a leading cause of heart failure. Indeed, while neonatal mammals can regenerate cardiac tissue mainly through cardiomyocyte proliferation, this ability is lost shortly after birth, resulting in the adult heart’s inability to regenerate after injury effectively. In adult mammals, the adverse cardiac remodelling, which compensates for the loss of cardiac cells, impairs cardiac function due to the non-contractile nature of fibrotic tissue. Moreover, the neovascularisation after MI is inadequate to restore blood flow to the infarcted myocardium. This review aims to synthesise the most recent insights into the molecular and cellular players involved in endogenous myocardial and vascular regeneration, facilitating the identification of mechanisms that could be targeted to trigger cardiac regeneration, reduce fibrosis, and improve functional recovery post-MI. Reprogramming adult cardiomyocytes to regain their proliferative potential, along with the modulation of target cells responsible for neovascularisation, represents promising therapeutic strategies. An updated overview of endogenous mechanisms that regulate both myocardial and coronary vasculature regeneration—including stem and progenitor cells, growth factors, cell cycle regulators, and key signalling pathways—could help identify new critical intervention points for therapeutic applications. Full article

LMNA-related dilated cardiomyopathy (DCM) is an autosomal-dominant genetic condition with cardiomyocyte and conduction system dysfunction often resulting in heart failure or sudden death. The condition is caused by mutation in the Lamin A/C (LMNA) gene encoding Type-A nuclear lamin proteins involved in nuclear integrity, epigenetic regulation of gene expression, and differentiation. The molecular mechanisms of the disease are not completely understood, and there are no definitive treatments to reverse progression or prevent mortality. We investigated possible mechanisms of LMNA-related DCM using induced pluripotent stem cells derived from a family with a heterozygous LMNA c.357-2A>G splice-site mutation. We differentiated one LMNA-mutant iPSC line derived from an affected female (Patient) and two non-mutant iPSC lines derived from her unaffected sister (Control) and conducted single-cell RNA sequencing for 12 samples (four from Patients and eight from Controls) across seven time points: Day 0, 2, 4, 9, 16, 19, and 30. Our bioinformatics workflow identified 125,554 cells in raw data and 110,521 (88%) high-quality cells in sequentially processed data. Unsupervised clustering, cell annotation, and trajectory inference found complex heterogeneity: ten main cell types; many possible subtypes; and lineage bifurcation for cardiac progenitors to cardiomyocytes (CMs) and epicardium-derived cells (EPDCs). Data integration and comparative analyses of Patient and Control cells found cell type and lineage-specific differentially expressed genes (DEGs) with enrichment, supporting pathway dysregulation. Top DEGs and enriched pathways included 10 ZNF genes and RNA polymerase II transcription in pluripotent cells (PP); BMP4 and TGF Beta/BMP signaling, sarcomere gene subsets and cardiogenesis, CDH2 and EMT in CMs; LMNA and epigenetic regulation, as well as DDIT4 and mTORC1 signaling in EPDCs. Top DEGs also included XIST and other X-linked genes, six imprinted genes (SNRPN, PWAR6, NDN, PEG10, MEG3, MEG8), and enriched gene sets related to metabolism, proliferation, and homeostasis. We confirmed Lamin A/C haploinsufficiency by allelic expression and Western blot. Our complex Patient-derived iPSC model for Lamin A/C haploinsufficiency in PP, CM, and EPDC provided support for dysregulation of genes and pathways, many previously associated with Lamin A/C defects, such as epigenetic gene expression, signaling, and differentiation. Our findings support disruption of epigenomic developmental programs, as proposed in other LMNA disease models. We recognized other factors influencing epigenetics and differentiation; thus, our approach needs improvement to further investigate this mechanism in an iPSC-derived model. Full article

Cardiovascular disease represents the foremost cause of mortality and morbidity worldwide, with a steadily increasing incidence due to the growth of the ageing population. Cardiac dysfunction leading to heart failure may arise from acute myocardial infarction (MI) as well as inflammatory- and cancer-related chronic cardiomyopathy. Despite pharmacological progress, effective cardiac repair represents an unmet clinical need, with heart transplantation being the only option for end-stage heart failure. The functional profiling of the biological activity of extracellular vesicles (EVs) has recently attracted increasing interest in the field of translational research for cardiac regenerative medicine. The cardioprotective and cardioactive potential of human progenitor stem/cell-derived EVs has been reported in several preclinical studies, and EVs have been suggested as promising paracrine therapy candidates for future clinical translation. Nevertheless, some compelling aspects must be properly addressed, including optimizing delivery strategies to meet patient needs and enhancing targeting specificity to the cardiac tissue. Therefore, in this review, we will discuss the most relevant aspects of the therapeutic potential of EVs released by human progenitors for cardiovascular disease, with a specific focus on the strategies that have been recently implemented to improve myocardial targeting and administration routes. Full article

Ischemic heart disease, which is one of the top killers worldwide, encompasses a series of heart problems stemming from a compromised coronary blood supply to the myocardium. The severity of the disease ranges from an unstable manifestation of ischemic symptoms, such as unstable angina, to myocardial death, that is, the immediate life-threatening condition of myocardial infarction. Even though patients may survive myocardial infarction, the resulting ischemia-reperfusion injury triggers a cascade of inflammatory reactions and oxidative stress that poses a significant threat to myocardial function following successful revascularization. Moreover, despite evidence suggesting the presence of cardiac stem cells, the fact that cardiomyocytes are terminally differentiated and cannot significantly regenerate after injury accounts for the subsequent progression to ischemic cardiomyopathy and ischemic heart failure, despite the current advancements in cardiac medicine. In the last two decades, researchers have realized the possibility of utilizing stem cell plasticity for therapeutic purposes. Indeed, stem cells of different origin, such as bone-marrow- and adipose-derived mesenchymal stem cells, circulation-derived progenitor cells, and induced pluripotent stem cells, have all been shown to play therapeutic roles in ischemic heart disease. In addition, the discovery of stem-cell-associated paracrine effects has triggered intense investigations into the actions of exosomes. Notwithstanding the seemingly promising outcomes from both experimental and clinical studies regarding the therapeutic use of stem cells against ischemic heart disease, positive results from fraud or false data interpretation need to be taken into consideration. The current review is aimed at overviewing the therapeutic application of stem cells in different categories of ischemic heart disease, including relevant experimental and clinical outcomes, as well as the proposed mechanisms underpinning such observations. Full article